This invention relates to tension-proof, impermeable, flexible bands which include at least one reinforcing band for acceptance of forces developed by tension and, more particularly, to a process for producing same.
The prior art underlying the invention was the manufacture of band by melting and calandering or PUR or spreading of liquid PUR, respectively. Those bands, however, must be provided within the web with a multifilament as a filling weft thread in order to avoid the penetration of the liquid PUR to the other side of the web and insofar to secure a precise spreading of the material on the surface of the web.
The band of the present invention embodies as a reinforcing band a fabric band which is permeated with a polymer such that the same is caused to develop a solid web on the fabric band and which web is in taut condition and caused to permeate the fabric band either by subjection to heating above its melting point so as to flow into the fabric band, or by a wiping-in or rolling-in of the heated polymer by means of a wiper blade or counter roller.
In the present process, wiping is not disregarded so that openings in the band may occur at least in a situation where the surface of the band is substantially ground smooth, through which openings a liquid, such as, for example, lubricating fluid, can flow from one side of the band to the other and, hence, permeate same under the application of pressure.
Therefore, it is an object of the present invention to provide a process for producing a flexible band of the type above indicated whereby a fluid impervious band is reliably obtained in a facil manner.
It is another object of the present invention to provide a process of the character stated whereby a flexible band embodying at least one reinforcing band is obtained by the utilization of readily available constituents and wherein the conditions for effecting the inter-reaction of the same may be accomplished in an economical manner.